On average, according to the National Cancer Institute, 609,640 people die from cancer each year. Now, what if I told you that none of these people had to die?
Nanotechnology. The whole world is mesmerised with it. But, what really is it? You see, nanosensors are chemical or mechanical sensors that can be used to detect the presence of chemical species and nanoparticles, or monitor physical parameters such as temperature, on the nanoscale. One nanometer is one-billionth of a meter, meaning it’s about as small as a single grain of sand.
Nanosensors are essentially magical devices that open up a whole new world of opportunities to expand our horizons for building devices. They are completely capable of interacting at the nanolevel with ease. Due to this, they can observe a unique process which cannot be done at the macro level. Nanosensors are just like any other sensor. They are a device used to measure a property, such as pressure, position, temperature, or acceleration, and respond with feedback.
There are two types of nanosensors — mechanical nanosensors and chemical nanosensors — which both have very different sensing mechanisms. Nanosensors that detect chemicals work by measuring the change in the electrical conductivity of the nanomaterial once an analyte has been detected. Many nanomaterials have a high electrical conductivity, which will reduce upon binding or adsorption of a molecule. It is this detectable change that is measured. Mechanical nanosensors also work by detecting a change in the electrical conductivity of a material. Nanomaterials that are used as mechanical nanosensors change their electrical conductivity when the material is physically manipulated, and this physical change invokes a detectable response. This response can also be measured using an attached capacitor, where the physical change creates a measurable change in the capacitance.
Now, the real reason why the world is currently going through a ‘Nano-Craze’ are for the following characteristics nanosensors have:
Nanosensors are highly sensitive, allowing them to accurately measure properties. They are also small, durable and light, allowing for them to be easily transported in large quantities. Additionally, they have very low power consumption, meaning that many of them can be running at the same time without much power cost. They also cause less disturbance to the observed material during the process. Because of their high speed, they can do real-time analysis. They can also detect multiple things at multiple times, making them perfect for a variety of applications, for example, detecting cancers inside the human body.
Nanofabrication is the design and manufacture of nanosensors and other nanostructures. There are two approaches to nanofabrication, the first one being top down fabrication. Top down fabrication when the base material is changed to the desired shape. The most common technique for this is nanolithography. This is where the material required is protected by a mask while the exposed material is cut away. This can be done using acids, ultraviolet lights, x rays and electron beams, depending on the level of resolution required by the nanostructure. Bottom up fabrication is when atoms or molecules are placed one by one to eventually create a nanostructure.
There are a few problems with both top down and bottom up types of nanofabrication. Top down fabrication is quite expensive, although is very much faster than bottom up fabrication. On the other hand, bottom up fabrication is a lot less expensive, but takes much more time to complete. Both of these methods are inefficient due to either cost, or time.
To improve nanofabrication while using bottom up fabrication, we can make it self assembling. In fact, many scientists are already trying this but there still are significant obstacles to overcome. It would take a lot longer to make nanofabrication efficient using this method. To make nanofabrication more efficient in a smaller period of time, we could find better materials and also use some elements from top down fabrication in bottom up fabrication. Eventually, nanofabrication will become efficient and cost effective.
Now, nanosensors and other nanostructures have a variety of different applications. From pollution monitoring to studying neurotransmitters in the brain, nanotechnology helps us understand neurophysiology better.
Quite recently, it has been discovered that nanotechnology can be used both detect and prevent cancers in the human body. Doesn’t that sound like magic? Through the use of nanotechnology, just imagine all the possibilities…